Stage light fittings are basically grouped into two types called “wash” and “spot”, respectively. Light fittings of “wash” type are characterized in that they project a light beam of diffused light, while light fittings of “spot” type are characterized in that they project concentrated light beams, and are capable of focusing images projected onto a surface hit by the light beam.
From a structural point of view, light fittings of “spot” type differ from light fittings of “wash” type due to the respective main optical assemblies: stage light fittings of “wash” type employ a main optical assembly including a Fresnel lens or more generally a plano-convex lens with the flat surface being milled or opacified, while the light fittings of “spot” type employ a main optical assembly comprising an objective lens and capable of focusing the projected images. Both the above-identified types of stage light fittings may be equipped with a plurality of optical devices arranged between the light source and the main optical assembly so as to produce light effects. Among the optical devices which are arranged between the light source and the main optical assembly, it is worth recalling the filters which, in turn, are grouped into coloured filters and filters adapted to shape the light beam, also known as “beam shapers”; the prisms adapted to divide the light beam emitted by the light source into two or more outgoing light beams, the shutters to shape the light beam; the gobo devices; the dimmers, etc.
The above-identified optical devices permit to obtain a plurality of light effects even considering that the stage light fittings are designed to intercept the light beam by means of one or more optical devices so as to combine the respective light effects. Although the stage light fittings available on the market offer the possibility of obtaining a plurality of light effects, the light designers, i.e. those who study and design light performances, are always looking for new possible light effects and combinations of light effects.